For an exoplanet to be detected via the astrometric method, it must
A) orbit its star with a component of its motion parallel to the line of sight to from the star to Earth.
B) orbit its star with a component of its motion perpendicular to the line of sight to from the star to Earth.
C) have a low albedo.
D) have a high albedo.

Question

Quizplus · Accepted Answer

The astrometric method detects exoplanets by observing the slight movements (wobbles) of a star around the common center of mass with its planet(s). This movement is most easily observed when the planet's orbit has a component perpendicular to our line of sight, causing the star to move side to side in the sky from our perspective.

For an Exoplanet to Be Detected Via the Astrometric Method